--- a/index.html	Tue Feb 28 00:03:15 2017 +0900
+++ b/index.html	Fri Jul 06 16:28:00 2018 +0900
@@ -6,7 +6,6 @@
 
     <style type="text/css">
         * {
-            position: relative;
             box-sizing: border-box;
         }
 
@@ -14,7 +13,7 @@
             height: 100%;
             margin: 0;
             padding: 0;
-            font-family: sans-serif;
+            font-family: Arial, sans-serif;
             font-size: 12px;
         }
 
@@ -28,14 +27,14 @@
             width: 100%;
             margin-bottom: 10px;
             resize: vertical;
-            font-family: monospace;
+            font-family: Courier New, monospace;
             /* prevent ios zoom */
             font-size: 16px;
         }
 
         .page {
             width: 100%;
-            height: 100%;
+            min-height: 100%;
             max-width: 600px;
             margin: 0 auto;
             display: flex;